1. Field of the Invention
The present invention relates to a sensing pixel structure, and particularly to a sensing pixel structure for generating a sense image with uniform resolution.
2. Description of the Prior Art
Please refer to FIG. 1, which is a diagram of an optical sensor 100 according to the prior art. The optical sensor 100 comprises a sensing pixel structure 110 and an optical lens 120. The sensing pixel structure 110 is placed corresponding to the optical lens 120. More specifically, a central region of the sensing pixel structure 110 is positioned corresponding to a central region of the optical lens 120, and a peripheral region of the sensing pixel structure 110 is positioned corresponding to a peripheral region of the optical lens 120. The sensing pixel structure 110 is used for receiving light through the optical lens 120 to generate a sense image SIM.
Please refer to FIG. 2, which is a diagram of the sensing pixel structure 110 according to the prior art. The sensing pixel structure 110 comprises B sense pixels CSU1-CSUB. As shown in FIG. 2, in the sensing pixel structure 110, each sense pixel CSU1-CSUB has the same pixel area AREAOLD. In other words, sense pixels (e.g. sense pixel CSUX) located in the central region of the sensing pixel structure 110 and sense pixels (e.g. sense pixels CSU1, CSUB) located in the peripheral region of the sensing pixel structure 110 have the same pixel area AREAOLD. In other words, the same number of sense pixels correspond to the peripheral region of the optical lens 120 as to the central region of the optical lens 120. Due to resolution of the central region of the optical lens 120 being better than that of the peripheral region of the optical lens 120, and the number of sense pixels corresponding to the peripheral region of the optical lens 120 is the same as to the central region of the optical lens 120. Thus, resolution of the sense image SIM generated by the sensing pixel structure 110 receiving light through the optical lens 120 is uneven (resolution of the central region is better than resolution of the peripheral region). For example, using the optical sensor 100 to sense a scene P shown in FIG. 3, the optical sensor 100 generates the sense image SIM shown in FIG. 4. It can be seen from FIG. 3 and FIG. 4 that the peripheral region and the central region have the same square patterns in the scene P, but because the central region of the optical sensor 100 has better resolution than the peripheral region, the square patterns in the peripheral region of the sense image SIM are distorted. Thus, when the user wants to perform further image processing on the sense image SIM, because the resolution of the sense image SIM is non-uniform, processing methods used on the peripheral region of the sense image SIM must be different from those used on the central region. This causes difficulty when the user performs image processing on the sense image SIM.